Vitamin K - phylloquinone

Question 1

what does the sidechains of vit K consist of

Answer 1

3 different chains for vit K1-3

Question 2

vit. K1

Answer 2

phylloquinone

- 20C, plant origin

Question 3

vit. K2

Answer 3

menaquinone

• 30, 35, 45C side chain
• microbial origin (meat, egg, liver)
• no storage in the liver

Question 4

vit. K3

Answer 4

menadione

• no side chain
• synthetic origin
• can be prod in the liver

Question 5

origin of vit K

Answer 5

plant: cabbage, chestnut leaves
animal: microbial: meat, egg, fish

Question 6

metabolism og vit K

Answer 6

absorbed in small int. and tp. with chylomicrons to the liver, since it cannot be stored it will be transported further to the organs in question. (lipoprotein)

Question 7

excretion

Answer 7

liver -> lipoproteins -> excretion via bile or urine (ox and bound to glucuronate)

Question 8

gamma carboxylation of Glu

Answer 8

is vit K dependant, and activates blood clotting factors and osteocalcin (together with Ca²⁺) = bone building protein secr. by osteiblasts

Question 9

vitamin K antagonists

Answer 9

warfarine - blocks epoxyreductase step
dicoumarol
–> both are anticoagulants

Question 10

vit K deficiency leads to

Answer 10

1. bleeding syndrome, decr. bone formation caused by antagonists
2. hemorrhage - reduced prothrombin (injury and spont.)

Question 11

reasons for vit. K deficiency

Answer 11

less bile acid synth .> less abs. of vit. K -> deficiency

microbial synthesis decr. -> K2 deficiency

• antibiotic treatment
• new born (placenta not perm to vit. K)
• poultry: short large int
• prevention of coprophagy (inj, imp vits made in colon?)